Selling a rental to individual home buyer

[Thomas Stanley]

I have a few low income rentals I bought a couple years back. I have someone who is interested in buying one house as a private home. Here's where it is getting complicated:

- I bought the houses in a package but still owe about 60% on the general mortgage.

- the house they are looking at is worth around 29k.

- The buyers are lower income hispanics (likely undocumented). they own the house across the street and did the same thing and own that house outright. 

- They can put down 5-6k now and pay 900-1000 a month.

- I don't know if I would get the full price outright any other way.

Ultimately I could imagine working something out so they pay the house off in 2 years. I would plan to put 100% of the payments onto my mortgage to pay down the principal. 

My questions are:

- Is this legal?

- What do i need to do to protect myself in case they move?

- Would it be similar to a rent to own set up without the rental expectation. 

I would appreciate your help!

Thomas